In September 2002, NOAA, in cooperation with the U.S. Coral Reef Task Force, released a National Coral Reef Action Strategy. The first of several goals defined within the strategy is to create comprehensive maps of all U.S. coral reef habitats. Specifically, the report calls for the production of comprehensive digital maps of all shallow (< 30 meters) coral reefs and the characterization of priority deep water (> 30 meter) reef systems in the U.S. and Trust Territories. Benthic habitat mapping and characterization is a fundamental component of ecosystem-based coral reef management because it integrates a variety of information to define the extent, nature and health of these ecosystems. Without accurate maps resource managers cannot make informed decisions.
To help address these goals, the NOAA Pacific Island Fisheries Science Center's Coral Reef Ecosystem Division established a benthic habitat mapping group. The group has established a collaborative effort with the University of Hawaii's Hawaii Mapping Research group. Named the Pacific Islands Benthic Habitat Mapping Center (PIBHMC), this collaboration is physically located at the University of Hawaii and is tasked with the delineation of the benthic habitat of coral reef ecosystems throughout the U.S. Pacific Islands, including the Hawaiian and Mariana archipelagos, American Samoa and the remote, U.S.-affiliated islands such as Johnston and Palmyra Atolls.
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Figure 1. Color-coded multibeam bathymetry from Kure Atoll and depths derived from satellite imagery (the gray-colored area in the center of the atoll) overlain on a nautical chart. Mapping on this cruise at Kure will concentrate on the donut-shaped area between these datasets.
PIBHMC uses acoustic and optical techniques to create benthic habitat maps in waters deeper than 20 meters where satellite and diver-based techniques are not feasible. Accurate, high-resolution habitat maps are essential for effective management of coral reefs. Products created by PIBHMC provide resource managers with comprehensive habitat maps on which to base decisions about Pacific coral reef ecosystems.
PIBHMC personnel support mapping missions on NOAA ships Hi'ialakai and Oscar Elton Sette and operate the NOAA Fisheries survey launch R/V Ahi. The data collected during these missions are used to create standard map products that are available to resource management agencies, researchers, and the general public.
For more information about PIBHMC visit their website at www.soest.hawaii.edu/pibhmc.
On cruise HI0609, the Hi'ialakai will spend a little over six days at Kure (see Figure 1) mapping around the clock with the shipboard Simrad EM300 and EM3002 multibeam systems. During the day, the Reson 8101 multibeam system aboard the launch R/V AHI will be used to survey the shallower waters of the area to be mapped. Overall, it is estimated that there are almost 1400 linear kilometers of survey track required to generate complete multibeam coverage of Kure Atoll. It is further estimated that that task will require approximately eight full days to complete, so we expect to have the majority of the atoll surveyed by the time we head to Pearl and Hermes.
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Figure 2. Multibeam bathymetry around the outer edges of Pearl and Hermes Atoll, with depths estimated from satellite imagery shown in red in the center of the atoll, overlain on a nautical chart. Mapping during HI0609 will concentrate on the areas lacking coverage between these two datasets.
The Hi'ialakai will spend approximately seven days at this atoll. Over 400 sq. kilometers (128 sq. mi.) of coral reef habitat remain to be surveyed here. That is estimated to require approximately 14 days to complete, so we only expect to finish about half of that task during this cruise.